This works well on my D5… although I could see the down-arrow, I couldn’t get to the drop-down menu, perhaps my fingers are too big…
This app is simple to use and works well. Unfortunately I confirm that it’s impossible to use the down-arrow even with small fingers. You have to use the app with default setting.
I quite like pale blue… 
Some apps just don’t work on the watch for no good reason, like “steamy windows” which I’m really disappointed about